SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0f96b63ab0c99971743576d4564366d49f4704d03088f6e338da9c69ee9b8d8' 
  AND token = '0/GBSXjDnKzLct/hgd7FeFnABXFXUPqj4E7F3ZqwvPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}